Paperboard container having reinforced corners

Abstract

The corrugated container is provided with internal reinforcing panels to form corners of increased thickness, thereby augmenting the stacking strength of the container. Locking tabs are formed in either vertical endwalls or in horizontal lid panels of the container and are interlocked with the reinforcing panels being folded between overlapping reinforcing panels. Locking slots are provided in the carton sidewalls and locking flaps have ear portions engagable with edges of the locking slots, to hold the lid panels in a closed position.

What is claimed is: 
     
       1. A carton having reinforced corners of multiple thickness, formed from a one-piece blank, comprising: a floor panel having two pairs of opposed sides;   a pair of opposed endwall panels hingedly connected to one pair of said opposed sides of said floor panel, the endwall panels each having opposed sides;   lid panels in serial succession with each of said endwall panels and hingedly connected to respective ones of said endwall panels along respective hinge lines;   a pair of sidewall panels hingedly connected to the remaining pair of said opposed sides of said floor panel, said sidewall panels each having a pair of opposed sides;   a reinforcing panel subassembly coupled to each side of said sidewall panels, with pairs of said reinforcing panel subassemblies overlain by a respective one of said sidewall panels, each of said reinforcing panel subassemblies comprising first, second and third hingedly connected reinforcing panels;   the first, second and third reinforcing panels arranged end-to-end in a series within each of the reinforcing panel subassemblies, with the first panel of each of said subassemblies hingedly connected to one of said sides of a respective one of said sidewall panels, the first and second panels of each of said reinforcing panel subassemblies folded over one another so as to overlap one of said endwall panels and so as to position the third panel of respective ones of said reinforcing panel subassemblies to overlap one of said sidewall panels; and   locking tabs extending from the endwall panels and folded between the first and second reinforcing panels to maintain the first, second and third reinforcing panels in position during assembly of the carton.   
     
     
       2. The carton of claim 1 wherein the first reinforcing panel of each reinforcing panel subassembly is notched to receive at least a portion of one of said locking tabs. 
     
     
       3. The carton of claim 1 wherein the third reinforcing panels, of reinforcing panel subassemblies which extend from a common one of said sidwalls, are dimensioned to butt against one another to further maintain the first, second and third reinforcing panels in position during assembly of the carton. 
     
     
       4. The carton of claim 1 wherein said locking tabs are located immediately adjacent said sidewalls to as to support opposed lateral edges of said endwalls. 
     
     
       5. The carton of claim 1 wherein the locking tabs are cut out mostly from the lid panels and, to a lesser extent, from the endwalls so as to extend from the endwalls with a hinged connection thereto. 
     
     
       6. The carton of claim 1 wherein the locking tabs are cut out from the endwalls so as to extend from the endwalls with a hinged connection thereto. 
     
     
       7. A carton having reinforced corners of multiple thickness, formed from a one-piece blank, comprising: a floor panel having two pairs of opposed sides;   a pair of opposed endwall panels hingedly connected to one pair of said opposed sides of said floor panels, the endwall panels each having opposed sides;   lid panels in serial succession with each of said endwall panels and hingedly connected to respective ones of said endwall panels along respective hinge lines;   a pair of sidewall panels hingedly connected to the remaining pair of said opposed sides of said floor panel, the sidewall panels extending between said opposed endwall panels with each said sidewall panel defining at least one locking slot, said at least one locking slot having a first end of preselected height extending toward one of said endwall panels and a second end of reduced height which second end extends toward the other of said endwall panels and which second end forms an acute angle portion pointing toward the other of said endwall panels, the locking slot defining a generally rectangular opening with the acute angle portion extending from one side of the rectangular opening; and   locking flaps extending from at least one of said lid panels, each locking flap having free ends forming locking ears for telescopic insertion through said locking slots and each having a connecting portion joining respective ones of the locking ears to respective ones of the lip panels so that said locking ears protrude beyond the connecting portions to which they are connected, toward the other one of said endwall panels.   
     
     
       8. The carton of claim 7 wherein the acute angle portion is partly formed by a concavely curved edge formed in said sidewall. 
     
     
       9. The carton of claim 8 wherein said locking ears each include a convexly curved edge portion which abuts the concavely curved edge of a respective locking slot when the locking ears are inserted in respective ones of said locking slots. 
     
     
       10. The carton of claim 9 wherein the convexly curved edge portions are located at the free ends of the locking flaps. 
     
     
       11. The carton of claim 9 wherein the locking ears include a fold line for bending the free ends toward each other during insertion into the locking slots.